Function validate_simple_case_expression

graphlite/src/ast/validator.rs:1236–1267

Validate simple CASE expressions

(
    simple_case: &SimpleCaseExpression,
    ctx: &mut ValidationContext,
    errors: &mut Vec<ValidationError>,
)

/// Validate simple CASE expressions
fn validate_simple_case_expression(
    simple_case: &SimpleCaseExpression,
    ctx: &mut ValidationContext,
    errors: &mut Vec<ValidationError>,
) {
    // Validate test expression
    validate_expression(&simple_case.test_expression, ctx, errors);

    // Validate WHEN branches
    for when_branch in &simple_case.when_branches {
        // Validate WHEN values
        for when_value in &when_branch.when_values {
            validate_expression(when_value, ctx, errors);
        }
        // Validate THEN expression
        validate_expression(&when_branch.then_expression, ctx, errors);
    }

    // Validate ELSE expression if present
    if let Some(else_expr) = &simple_case.else_expression {
        validate_expression(else_expr, ctx, errors);
    }

    // Check that there's at least one WHEN branch
    if simple_case.when_branches.is_empty() {
        errors.push(ValidationError {
            message: "CASE expression must have at least one WHEN branch".to_string(),
            location: Some(crate::ast::Location::default()),
            error_type: ValidationErrorType::Structural,
        });
    }
}

/// Validate searched CASE expressions
fn validate_searched_case_expression(